Blumea 59, 2014: 144–154 www.ingentaconnect.com/content/nhn/blumea RESEARCH ARTICLE http://dx.doi.org/10.3767/000651914X685861

Expansion of the Nepenthes alata group (Nepenthaceae), Philippines, and descriptions of three new species

M. Cheek¹, M. Jebb²

Key words Abstract Three new species in the Nepenthes alata group from the Philippines, Nepenthes armin, N. tboli and N. zygon, are described and assessed as threatened using the IUCN 2012 standard. The group is expanded by conservation the inclusion of N. truncata and N. robcantleyi, previously included in the N. regiae group. A key to the nineteen IUCN species of the group is presented. mining Nepenthes Published on 11 December 2014 Philippines taxonomy ultramafic

INTRODUCTION of Samar, northwest Panay Peninsula and Mindoro. Moderate forest disturbance can favour the growth of some Nepenthes This paper is part of the research towards a World Monograph species, particularly a small number of widespread lowland SE of Nepenthes L., building on a Skeletal Revision of Nepenthes Asian species such as N. gracilis Korth. which can colonise (Jebb & Cheek 1997) and the Flora Malesiana account (Cheek secondary habitats. However, this is not true of the majority & Jebb 2001). of Nepenthes species, which are both more localized and Nepenthes is the only genus of Nepenthaceae and includes which require primary habitat. It also appears to be the case taxa mainly distributed in Malesia (c. 128 species), while c. 12 that primary habitat is not just degraded to secondary habitat species occur in Madagascar, Seychelles, Sri Lanka, NE India, in the Philippines, but converted to other land uses, such as Indochina, Solomon Islands, New Caledonia and Australia. rice-fields, open cast mines, or pineapple plantations, offering Cheek & Jebb (2001) recorded 87 species of Nepenthes, but little chance for survival for even those species that can survive since 2001, 60 new specific names have been published in secondary habitats. the genus (see IPNI 2013 continuously updated, acc. 17 Dec. Many species of Nepenthes in the Philippines appear to be 2013) and others have been resurrected from synonymy. The confined to submontane forest (above c. 500 m asl) and are number of species currently accepted is estimated as 140 and confined to individual mountain groups or mountains of one is set to rise further. island. Compared with lowland forest, a higher proportion of Cheek & Jebb (2001) recorded 12 species in the Philippines. submontane forest survives, since it is often less suitable for New field surveys and herbaria examinations resulted in the agriculture. While N. alzapan may yet survive since some discovery of 26 additional species that have been published submontane forest habitat in the Sierra Madre Mts can still be in the last twelve years (see IPNI 2013 continuously updated, found (e.g. viewing with Google Earth), the hopes for N. extincta e.g. Heinrich et al. 2009, Cheek 2011), of which 12 were surviving are extremely small, since recent groundtruthing has published in 2013 (Cheek & Jebb 2013a–h). Some taxa e.g. shown that virtually all vegetation has been removed from its Nepenthes alzapan Jebb & Cheek (Cheek & Jebb 2013b: 59) single location to facilitate extraction of nickel ore (Cheek & and Nepenthes extincta Jebb & Cheek (Cheek & Jebb 2013h) Jebb 2013h). Since habitat destruction for open cast mining, were considered possibly extinct since the destruction of timber extraction, small-holder, swidden and plantation agri- original habitat in the Philippines over the last 100 years has culture continues in the Philippines, it is a race against time to been so extensive. Although the Philippines is thought to have discover, publish, assess and draw attention to the conservation remained two-thirds forested as recently as 1925 according needs of species before they become extinct, if they have not to Sohmer & Davis (2007), 75 years after that date Myers et already been lost. al. (2000) estimated that remaining primary vegetation in the The Nepenthes alata group of species was first circumscribed Philippines amounted to only 3 %. Lowland primary forest is in Cheek & Jebb (2013d) and additional taxa were added by very fragmentary or has now all but gone from the Philippines Cheek & Jebb (2013c, f). The group was redelimited with the (Sohmer & Davis 2007). They define lowland forest as occur- addition of four species in Cheek & Jebb 2013h. With the addi- ring below 500 m asl. Sohmer & Davis (2007) estimate species tion of three new species described here as well as two species extinction levels due to habitat destruction as 9–28 % in one previously placed in the N. regiae group, N. truncata and N. rob- representative, mainly forest genus, Psychotria L. (Rubiaceae). However, some good lowland forests are reported to survive cantleyi, we now characterise the N. alata group as follows: in the provinces of Aurora, Cagayan, Isabela in Luzon, parts 1. possessing a convex appendage on the basal ridge of the lid (except in N. armin) but lacking an apical appendage; 1 Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK; corresponding author e-mail: [email protected]. 2. a wingless (except in N. saranganiensis), terete (rarely an­ 2 National Botanic Gardens, Glasnevin, Dublin 9, Ireland. gular) stem;

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3. a distinct but winged petiole, the petiole wings wide, decur- Nepenthes locations. For the Philippines also, Google Earth rent from the blade, sometimes involute giving a cylindrical also has a large number of photographs embedded within the appearance to the petiole; imagery enabling an assessment to be made of the quality of 4. the peristome finely ridged, the outer edge not, or only vegetation on the ground. Searches on Google regarding the slightly lobed; locations can also provide additional data on threats on the 5. the inner surface lacking conspicuous teeth; ground, especially where local conservationists have observed 6. the mouth ovate, oblique, without a well-developed column malpractice by commercial land developers or where National (except N. kitanglad); hairs fine and soft, inconspicuous, not Parks have been compromised. bristle-like (except N. mindanaoensis). The three species described here possess all, or almost all, of KEY TO THE SPECIES OF THE NEPENTHES ALATA these characters and we place them into an expanded definition GROUP of the N. alata group. They were discovered by examining (updated from Cheek & Jebb 2013h) specimens mainly from BRIT, E and L. 1. Lower surface of lid, including convex appendage (if devel­ The Nepenthes alata group (19 species restricted to the Phil- oped), densely and evenly covered by uniformly minute, ippine islands excluding Palawan) and the N. regiae group cir­cular nectar glands (0.15–0.2 mm diam) . . . . . 2 (14 species restricted to Borneo, Sulawesi and New Guinea) 1. Lower surface of lid with nectar glands either absent from are similar and appear closely related, as was discussed in the appendage (if developed), and/or sparse, large or Cheek & Jebb 2013h, where a key separating the two groups dimorphic, (larger glands 0.35–0.4 mm diam or larger). was presented. Application of this key to the two Philippine — Visayas and Mindanao ...... 5 species previously ascribed to the N. regiae group, namely N. truncata Macfarl. and N. robcantleyi Cheek places them also 2. Stems angular; convex basal appendage absent from lid; in the N. alata group, by reason of their winged petioles and male pedicels 3.5–4.5 mm long. — Sibuyan Island . . ovoid-cylindrical pitchers. A key to the currently recognised taxa ...... N. armin in the N. alata group is given below. We hypothesise that the 2. Stems terete; convex basal appendage conspicuous from lid; male pedicels > 10 mm long ...... 3 divergence of these two species groups from each other is con- nected with the geographical division between Borneo (centre 3. Stems glabrous, rarely glabrescent; upper pitcher lacking of species diversity of the N. regiae group) and Mindanao Island fringed wings; outer surface < 20 % covered with red stel- (centre of diversity of the N. alata group) of the Philippines. A late hairs or lacking them entirely ...... 4 molecular phylogenetic study of these two groups with high 3. Stems persistently pubescent; upper pitchers with fringed species sampling might help to test this hypothesis. However, wings in upper part; outer pitcher surface > 50 % covered it is also possible that further discoveries of additional species with grey stellate hairs. — Northern Luzon . . N. alata will provide evidence that the two groups are a continuum and 4. Upper pitchers subcylindrical, outer surface 10–15 % co­ should be united. vered with minute red stellate hairs. — Lowland coastal ultramafic scrub of N and E Luzon ...... N. ultra 4. Upper pitchers with ellipsoid base constricted abruptly to Materials and Methods the narrow, cylindrical upper 2/3; outer pitcher surface Herbarium specimens (codes for herbaria are according to Thiers lacking stellate hairs. — Lowland to submontane forest or scrub of southern Luzon to Mindanao . . N. graciliflora 2011 continuously updated) and living plants were examined. In several cases, the mouth and the lid surface are not readily visible 5. Stems winged from the decurrent petiole bases. — S Min­ in herbarium specimens, so it was necessary to soak the mouth da­nao, Sarangani Province . . . . N. saranganiensis area and lid, or sometimes the entire pitchers, in warm soapy 5. Stems terete, or angular, lacking wings ...... 6 water after requesting permission from the herbarium concerned. 6. Upper pitchers widest at apex ...... 7 The following characters were measured: stem, leaf and pitcher 6. Upper pitchers subcylindric, widest at base, or equally wide (using a graduated rule). Hair sizes, and peristome and lower at base and apex ...... 8 lid details were measured using a binocular microscope with 7. Stems and abaxial surface of midrib moderately densely an eyepiece graticule graduated in units of 0.025 mm at ×40 covered with white appressed hairs 0.5–1.5 mm long; lid of magnification. upper pitchers ovate, longer than broad. Volcanic substrate. Conservation assessments were made using the categories and — Mts Apo and Matutum, Mindanao . . .N. copelandii criteria of IUCN (2012). IUCN advises that assessments are 7. Stems and leaf blades glabrous; lid of upper pitcher broader than long. Ultramafic substrate. — Mt Kiamo, Mindanao made if at all possible, even when the data are incomplete, since ...... N. ceciliae full data are rarely available for any taxon, and since a threat- ened taxon may become extinct while waiting for full data to 8. Petioles appearing cylindrical (wings incurved) . . . 16 become available. All three of the taxa assessed in this paper 8. Petioles appearing flat, at least distally (wings held flat) 9 were assessed using criterion D, which is based on the numbers 9. Stems and lower surface of midrib conspicuously long and of mature individuals that can be evidenced. Data on numbers densely pubescent; lid appendage well-developed, hook­ of mature individuals derives from herbarium specimen data and ed ...... 10 from the reports of Nepenthes enthusiasts, many of which visit 9. Stems and upper surface of midrib glabrous or inconspicu- the Philippines every year from Germany, USA, Australia and ously and shortly and sparsely pubescent-puberulent; lid ap- France to seek species of this genus in the wild, and especially pendage usually only moderately developed, never hooked taxonomic novelties and rare and poorly known taxa. These ...... 12 same enthusiasts are also a source of information on threats 10. Upper pitchers equally wide at base and apex, contracting at Nepenthes locations, as are a growing number of Philip- slightly at the middle, lacking fringed wings. — NE Minda­ pine observers. A key source of data on threats on the ground nao ...... N. ramos is Google Earth. For much of the Philippines high resolution 10. Upper pitchers widest at base, contracting slightly above satellite imagery is available through this portal, enabling the into a narrower cylinder with a short pair of fringed wings encroachment to be viewed of e.g. plantations towards known near the mouth ...... 11 146 Blumea – Volume 59 / 2, 2014

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h i j k Fig. 1 Nepenthes armin Jebb & Cheek. a. Habit, male inflorescence, stem section quadrangular (inset below), and upper pitchers (detached); b. upper pitchers; c. sessile depressed-globose glands on lower surface of leaf-blade; d. hairs on midrib, adaxial surface of leaf; e. male flower; f. indumentum of lower tepal surface; g. indumentum of outer pitcher surface; h. peristome showing inner edge (dissected); i. peristome, viewed from inside pitcher, teeth not visible; j. peristome viewed from above; k. peristome, transverse section (outer surface on right); l. lower surface of lid; m. basal ridge in profile, convex appendage absent, with nectar glands, lower surface of lid; n. nectar glands, central area of lid; o. nectar glands, from lower surface of lid, lateral area; p. spur (all from Argent & Reynoso 8936). — Scale bars: a, b = 5 cm; c, d, g–k, n–p = 1 mm; e, m = 2 mm; f = 0.5 mm; l = 1 cm. Drawing by Andrew Brown. M. Cheek & M. Jebb: Expansion of the Nepenthes alata group 147

11. Leaf blades long, over 21 cm in length, midrib of lid with internodes (1.2–)1.8–4.2(–4.9) cm long; axillary buds not seen; numerous more or less circular glands 0.15–0.40 mm indumentum absent apart from dense brown simple hairs in diam. — Negros and Biliran Islands . . . . N. negros the leaf axils, otherwise only with sessile depressed-globose 11. Leaf blades of climbing stems short, less than 18 cm in glands 0.04 mm diam throughout. Leaves thinly coriaceous, length, nectar glands more or less absent from distal half petiolate narrowly oblong-elliptic to narrowly elliptic-linear, of lid midrib, glands larger 0.5–0.6(–0.7) mm. — NE Min­ (10–)13.1–15(–17.5) by (1.4–)1.8–2.6(–3.7) cm; apex acute danao ...... N. zygon or obtuse-rounded; base gradually decurrent to the petiole; 12. Lid apex with pocket. — S Cotabato, S Mindanao . . . nerves visible on the upper, not the lower, surface; longitudi- ...... N. tboli nal nerves 2 pairs, in the outer third of the leaf, the innermost 12. Lid apex lacking pocket or any appendage . . . . 13 pair arising from the midrib 1/2–1/3 the length of the blade from the petiole; pennate nerves numerous, patent, irregular; 13. Petiole canaliculate proximally (flat distally); blade hairy on indumentum absent except for simple hairs along the upper upper surface ...... 14 surface of the midrib, hairs (0.1–)0.4–0.6 mm long, erect, 13. Petiole flat proximally; blade glabrous on upper surface pale brown, covering (5–)20–40 % of the surface, densest in ...... 15 the distal half of the blade, otherwise with sessile glands as 14. Upper pitchers stout, length : breadth ratio 2–2.5 : 1; fring­ the stem, 10–12 glands per mm2. Petiole (4.2–)4.7–5.6(–7) ed wings absent. — Mt Hamiguitan, SE Mindanao . . by (0.2–)0.3–0.4(–0.6) cm, wings patent in life (revolute in ...... N. hamiguitanensis herbarium specimens), base clasping the stem by 1/2 its 14. Upper pitchers slender, length : breadth ratio > 3 : 1; fring- circumference, not decurrent, indumentum absent apart from ed wings present below peristome. — NE Mindanao . . sessile glands, and with very sparse and inconspicuous simple ...... N. zygon hairs along the abaxial midrib. Lower and intermediate pitch- 15. Stems terete; upper pitcher with lid about half as long as ers unknown. Upper pitchers (coiled tendril) green, with faint mouth; mouth not concave but flat; column absent; lid base purple mottling, narrowly cylindrical in outline, 10.2–12.9(–16) truncate. — Mt Malindang, NW Mindanao . . N. kurata by 1.9–2.6(–3.2) cm, the lower half narrowly ellipsoid, gradu- 15. Stems angular; upper pitcher with lid about as long as ally constricted to 1.3–1.8(–2.2) cm wide at the midpoint, then mouth; mouth highly concave; column present; lid base widening gradually to (1.7–)2.2–2.8(–3.2) cm wide below the cordate. — Kitanglad Mts, Central Mindanao N. kitanglad peristome; fringed wings absent, reduced to inconspicuous 16. Leaf-blade length : breadth about 1 : 1, apex deeply and ridges c. 1 mm wide extending from base to apex; indumentum 2 broadly notched ...... 17 of minutely branched hairs 0.1–1 mm long, 16–20 per mm , the 16. Leaf-blade length : breadth about 4 : 1, apex acute or ob­ smallest hairs with 2–3 branches at the base, the longer hairs tuse ...... 18 with 1–2 short branches along their length, mixed with sessile depressed-globose glands 10–12 per mm2. Mouth broadly 17. Largest pitchers with fringed wings from base to apex; peri­ ovate, 1.8–2.5(–3.8) by 1.8–2.3(–2.4) cm, oblique, slightly stome broad and flat at rear; lid nectar glands restricted to concave, column not well-developed; peristome cylindric, 1–2 a dome-like area around the basal appendage. — E Min- mm diam, ± even in width along its length, ribs 0.25 mm apart, da­nao ...... N. robcantleyi raised 0.04–0.08 mm, inner edge inrolled, teeth and holes 17. Largest pitchers without fringed wings; peristome outer visible only when dissected (Fig. 1h), outer edge often with edge rounded at rear; lid nectar glands scattered over lid; 2–3 shallow lobes; inner surface of pitcher glaucous green dome-like area absent. — NE and Central Mindanao . with scattered purple mottling. Lid orbicular, (1.8–)2.3–2.7 by ...... N. truncata (1.8–)2.1–2.6(–3.3) cm, apex rounded, or rarely emarginate, 18. Largest pitchers robust, 18–24 cm long; peristome 7–8 mm base cordate, sinus 3–4 mm deep, 10 mm wide; lower surface wide, curved in section but not cylindric; inner edge of brightly mottled purplish red, basal ridge c. 1 mm high 3 mm peristome with small teeth visible, outer edge lobed . 19 in length, convex basal appendage absent; nectar glands 18. Largest pitchers 12 cm long; peristome 2–3 mm wide, nar- evenly and densely spread across the lid and ridge surface, rowly cylindrical, inner edge lacking visible teeth (unless (4–)6–8(–10) per mm2, monomorphic, directed to lid base (rims dissected), outer edge not lobed. — Leyte . . .N. leyte are asymmetric, being highest towards lid apex ), orbicular, 0.2 19. Largest pitchers without fringed wings; leaf midrib densely, mm diam, with membranous walls projecting vertically, 0.07 minutely white stellate-hairy; pitcher lid base deeply cor- mm tall; mixed with sessile depressed-globose glands 0.04 mm date. — NE Mindanao ...... N. extincta diam at the edge of the lid, which are otherwise absent from the 19. Largest pitchers with fringed wings; leaf midrib with brown larger, central part of the surface. Spur recurved, simple, 3.5–5 black bristle hairs 1–1.5 mm long; pitcher lid base truncate. mm long, tapering to an acute apex, base completely covered — N and NE Mindanao ...... N. mindanaoensis in appressed hairs 0.2–0.3 mm long, simple, copper-coloured, distal three-quarters 50 % covered in hairs. Male inflorescence Nepenthes armin Jebb & Cheek, sp. nov. — Fig. 1 25–28 by 1.2–1.5 cm, indumentum of appressed, simple, copper-coloured hairs 0.3–0.4 mm long covering 40–50 % of Differs from N. graciliflora Elmer in the pitchers as wide at apex, or wider, than the surface, mixed with sessile depressed-globose glands as at base (not widest at base); convex lid appendage absent (not present); the stem; peduncle 7–11 by 0.1–0.2 cm; rhachis 17–18 cm long, androecium: tepal length ≤ 1 : 1 (not 2 : 1). — Type: Argent & Reynoso 8936 with 70–95, 1-flowered partial-peduncles; bracts absent; partial- (holotype K; isotypes E, PNH n.v.), Philippines, Sibuyan Island, above Magdi­ peduncles/pedicels 3.5–4.5 mm long, indumentum covering wang on ridge to Mayos Peak, 750 m, male infl. 16 Aug. 1989. 80–100 % of the surface; tepals 4, green at anthesis, turning Etymology. Named after Armin Rios Marin, Municipal Councilor on Sibu- red with age, 2.4 by 1.2–1.6 mm, outer surface completely yan and former World Wildlife Fund official who, on 3 October 2007, was covered in appressed, simple, copper-coloured hairs 0.2 mm shot and killed by a mining company official while leading a protest of his long, papillae absent or inconspicuous, inner surface densely community against the clearance of forest trees to facilitate mining (Good­ covered in elliptic nectar glands; staminal column 1–1.7 mm land & Wickes 2008: 175); [http://www.piplinks.org/system/files/Mining+or+ Food+Case+Study+6.pdf]. long, glabrous; anther-head subglobose, 0.45–0.9 by 1.2 mm. Female inflorescence as the male, but c. 30 by 1.2 cm; peduncle Terrestrial climber 5 m tall. Rosette and short stems unknown. c. 16 cm long; rhachis c. 14.5 cm (immature), partial-peduncles/ Climbing stem rounded-quadrangular (3–)4–5(–5.5) mm diam; pedicels c. 110, 3.5–6 mm long, tepals narrowly oblong 2.8 by 148 Blumea – Volume 59 / 2, 2014

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Fig. 2 Nepenthes tboli Jebb & Cheek. a. Habit, with upper pitchers and infructescence; b. leaf-blade midrib, lower surface, indumentum; c. hairs in axil of leaf with stem; d. hairs, on tendril; e. hairs on outer pitcher surface; f. hairs on outer pitcher wall, profile view; g. lid, lower surface, showing nectar glands (left) and venation (right); h. basal appendage of lower lid surface; i. large nectar glands of the lid midline; j. lid apex showing pocket; k. minute stellate hairs of lid margin, lower surface; l. spur; m. peristome from above; n. peristome, transverse section (outer surface: right) (all from Gaerlan et al. PPI 130838). — Scale bars: a = 5 cm; b, h–j, n, m = 2 mm; c–f = 1 mm; g, l = 1 cm; k = 0.1 mm. Drawing by Andrew Brown. M. Cheek & M. Jebb: Expansion of the Nepenthes alata group 149

1.2 mm, outer surface densely papillate with hairs sparse, scat- Table 1 Diagnostic characters separating N. graciliflora from N. armin. tered; ovary ellipsoid, 4-lobed, 2.2–3 by 1.1–1.4 mm completely Nepenthes graciliflora Nepenthes armin covered in hairs as the pedicels; stigmas glossy black, 4-lobed, 1.25 mm diam. Infructescence and seeds unknown. Data on Upper pitcher shape Basal third much wider Basal part as wide as, or than cylindric upper parts, narrower than, apex. colour and posture when live in this description is taken from lacking a waist constriction Constricted slightly in the the field notes of the specimens cited. middle Distribution & Ecology — Philippines, Sibuyan Island, gallery Convex lid basal Conspicuous Absent forest on ultramafic rock; 750 m. appendage Pitcher indumentum Hairs all simple, sparse, Hairs minutely branched, 2 Additional material. Philippines, Sibuyan Island, Mt Giting-Giting, Madulid < 1 per mm mixed long and subsimple 6927 (A, F, PNH n.v.), female inflor. 20 June 1987; ibid, Magdiwang, Barrio (appearing simple but with one or two very short and Hawasan, Ating River, Stone et al. in PPI 6724 (BISH, BRIT, K, PNH n.v.) inconspicuous branches), male inflor. 27 May 1992. with short, substellate, dense, 16–20 per mm2 Conservation — Nepenthes armin is known on current evi- Pedicel length at 11–14 mm 3.5–4.5 mm dence from three mature individuals (specimens cited above) anthesis which occur at up to three sites on Sibuyan Island (445 km2). Ratio of length of 2 : 1 < 1 : 1 Clearance of lowland forest trees on Sibuyan to facilitate mining androecium: tepals for nickel ore is reported by Goodland & Wickes (2008: 175); Indumentum at centre Mainly papillate, with a Completely covered in of male tepals few sparse hairs long appressed hairs, [http://www.piplinks.org/system/files/Mining+or+Food+Case+ (lower surface) papillae not visible Study+6.pdf]). Lowland forest below 750 m altitude on Sibu­ yan has also been partially cleared for lowland agriculture (Google Earth 2014 imagery, viewed 26 Sept. 2014). The area Notes — Nepenthes armin is the fourth species of Ne- of occupancy is a maximum of 12 km2 using the 4 km2 cells penthes known from Sibuyan. All but the widespread N. gra- advocated by IUCN (2012), although the actual area occupied ciliflora (Luzon to Mindanao) are known to be endemic to the is far smaller. Accordingly, N. armin is here assessed as Criti- ultramafic substrate of the island. The other endemic species cally Endangered under criterion D (< 50 mature individuals) of are known from low shrubberies on ultramafic at higher altitudes the categories and criteria of IUCN (2012). None of the three (1300–1400 m altitude), being N. argentii Jebb & Cheek and records of the species indicate its frequency. However, previ- N. sibuyanensis Nerz. Nepenthes armin is unlikely to be con- ous extensive botanical collections on Sibuyan by Elmer in the fused with any other species apart from N. graciliflora, which is early twentieth century did not reveal this species suggesting also a climber with petiolate leaves and pitchers which are nar- that it is not widespread and common on the island and may be rowly cylindrical in outline. They can be separated using Table 1. as rare and restricted as current evidence suggests. Regular The species-richness of Nepenthes in Sibuyan, with four spe- visits by Nepenthes enthusiasts to Sibuyan have occurred each cies of which three are endemic, equals that of the islands of year in the last few years but as yet, no additional records for Luzon, Panay and Masbate combined. Sibuyan measures this species have been publicised. However, it is to be hoped less than 30 by 20 km, but has a height of 2 058 m. Due to the that further survey work might yet result in finding numerous steep slopes, over 30 % of the island still has intact original additional individuals in secure locations. forest habitat, unusual in the Philippines, as explained in the Taxonomic affinities — The affinities of N. armin are clearly introduction above. In the Philippine archipelago, only Minda­ with N. graciliflora, in the N. alata group as defined in Cheek & nao and Palawan island exceed Sibuyan for endemicity and Jebb (2013d), in fact the two species can be easily confused species-richness of the genus Nepenthes. This diversity is not owing to their superficial gross morphological similarity. It is due to recent speciation, as has occurred on the Galapagos, for possible that the two species are sympatric, since both occur example, but is due to all of the three main Philippine Nepen- in forest below 800 m in Sibuyan. Records of N. graciliflora on thes lineages (Cheek & Jebb 2013h) having reached Sibuyan, Sibuyan are: Elmer 12465 (BO, E, K, W); Sohmer 12400 (A, and then having evolved there in isolation to form unusual BISH, K, L) and Reynoso 118659 (K, PNH n.v.). endemic species, including one of the most distinctive in the Nepenthes armin fits well within the northernmost, Luzon spe- entire family Nepenthaceae, N. argentii. In terms of Nepenthes, cies of the N. alata group, namely N. alata, N. graciliflora, Sibuyan appears to have the highest species diversity per unit and N. ultra Jebb & Cheek (Cheek & Jebb 2013f). In com- area of any island in the Philippines, which may be an index parison with species from the southern Philippines, these of diversity for other Philippine plant species. This surprising four northern species share relatively smaller upper pitchers fact is undoubtedly due to the large quantity of ultramafic sub- 10(–15) cm long, narrowly cylindrical peristomes, lids densely strate (unfortunately a source of metal ores), the broad altitu- and uniformly covered in steep-walled, small, monomorphic dinal range, and also the long geological isolation of Sibuyan nectar glands, and 1-flowered partial-peduncles. Nepenthes from other islands. The lack of disturbance and high levels of armin is easily separated from the remaining northern species intact original habitat are also explanatory factors. due to the slightly lobed outer edge of the peristome, and the angular-terete stems. The absence of a convex basal lid ap- Nepenthes tboli Jebb & Cheek, sp. nov. — Fig. 2 pendage, although unusual in the N. alata group, is also seen in N. kitanglad Jebb & Cheek. However, in both cases a basal Differs from N. saranganiensis Sh.Kurata in the stems terete (not 4-winged); ridge remains. Despite the unremarkable gross morphology of leaf-blade midribs and margins hirsute (not glabrous); pitcher lid apices retuse its pitchers, N. armin shows several features which are, so far, (not rounded). — Type: Gaerlan, Sagcal & Romero in PPI 13083 (holotype BRIT!; isotype L! sh. 0099289), Philippines, Mindanao, South Cotabato Pro­ unique in the N. alata group: vince, T’Boli, Lake Parker, 1463 m alt., male fl. & fr. Aug 1993. – The inflorescences with their very short pedicels and sta­ minal columns, and the dense covering of short, copper- Etymology. Named, as a noun in apposition, for the T’boli people and area from whence the type specimen derives. coloured appressed hairs. – The absence of sessile depressed-globose glands from the Terrestrial shrub or climber to at least 0.5 m tall. Rosette and centre of the lid. climbing stems unknown. Short stems terete, 0.4–0.6 cm diam. 150 Blumea – Volume 59 / 2, 2014

Leaves spirally inserted, internodes 1.5–2.6 cm long, epi- Table 2 The more important diagnostic characters separating N. saranga­ dermis drying black, wrinkled, moderately densely covered niensis and N. tboli. in red sessile globose glands 0.05 mm diam; very young Nepenthes saranganiensis Nepenthes tboli stems c. 50 % covered in red-brown, curved-erect, simple or 2(–3)-armed hairs 0.1 mm tall, concentrated in and near leaf Stem Prominently 4-winged Terete Indumentum of Absent Leaf edge hairy; abaxial axils; older stems with hairs 0.1–0.25 mm long c. 5 % covered stem and leaf leaf midrib and young and appearing glabrous. Leaf blades oblong-elliptic, 11–16 stem 50 % covered by by 2.8–3.5 cm; apex attenuate, base decurrent; longitudinal indumentum and pennate nerves not conspicuous, barely visible only on Peristome width (3.5–)5–9 mm 2–2.5 mm (side) lower surface, longitudinal nerves 5–10 pairs, oblique, arising Lower lid basal ridge Lacking appendage Well-defined, glandular at intervals along midrib as pennate nerves, arching upwards with appendage? appendage c. 1.5–2 by before running along and adjacent to margin for 0.5–1 cm; 2 mm indumentum absent from upper surface, except leaf edge Outer pitcher surface Densely stellate, with Sparsely puberulent (c. 5 % sparse long hairs cover) with simple, bifur- which is densely hairy, hairs 2–3-branched from the base or cate and bushy hairs from the main axis, 0.25–0.75 mm long; lower surface with Largest lid nectar 0.3–0.5 mm diam, 1–1.25 by 0.6–1 mm, red, sessile, globose glands c. 0.5 mm diam, c. 4 per mm2; glands of lower scattered along midline confined to band along midrib moderately densely hairy, c. 50 % cover, hairs simple, or surface and margin midline basally bi- or trifurcate 0.5–0.7 mm long, mixed with shrubby, Pitcher lid apex Rounded Retuse multi-armed hairs 0.25 mm diam. Petioles with patent wings, 4.5–6 by 0.6–0.9 cm, margin with white, sparsely branched, patent hairs 0.25–0.5 mm long; base clasping the stem for c. 50 % covered by mainly appressed white, heterogenous 1/2–2/3 its circumference, shallowly winged, subauriculate. hairs: bristle-like hairs 1–2-armed from base, 0.1–0.2 mm long; Lower and intermediate pitchers unknown. Upper pitchers vermicular, septate hairs c. 0.2 mm long, and by erect, minute (tendril coiled) narrowly subcylindrical, 11.5–17.5 by 3.5–4 cm; simple hairs 0.05 mm long; partial-peduncles 3 per mm length broadest at base, gradually tapering to 2.5–3 cm wide at the of rhachis, lacking bracts, 2-flowered, (1–)2 mm long; pedicels centre, gradually dilating towards apex, to c. 3.5 cm wide below divaricate, (8–)9–11 mm long; sepals ‘yellow-green’, 4, elliptic, the peristome; fringed wings absent, reduced to ridges; outer c. 0.6 by 0.4 mm, apex obtuse, inner surface densely covered surface minutely and sparsely puberulent, c. 5 % covered with in nectar glands, margin densely felted in rust-red papillae; erect red hairs, c. 7 per mm2, hairs bifurcate at base or apex, outer surface c. 40 % covered in white appressed hairs 0.1 mm or bushy, sessile, 0.15 mm long, or (c. 1 in 20 hairs) 3 mm long; androphore 3 mm long, basal 1/3–2/3 with patent long, patent, with 2–3 short lateral branches. Mouth ovate, white hairs 0.1 mm long, distal part glabrous; anther-head 3–5.3 by 3.7–4 cm, oblique; peristome subcylindric, 2–2.5 subglobose, wider than long, 1.5 by 1.75 mm, anther thecae mm wide, ridges 0.15–0.2 mm high, 0.3 mm apart, outer edge c. 15, uniseriate, dull yellow. Infructescence peduncle 25–26 tightly inrolled, not lobed, inner edge slightly incurved, teeth cm long, 0.4–0.6 cm diam at base, very sparsely puberulent; absent, perforated with holes, mostly clearly visible near the rhachis 12–13 cm long, indumentum as midrib of leaf, c. 60 % weakly developed column. Lid ovate or ovate-elliptic; 3–3.8 by of surface covered; partial-peduncles 30–36; 7–10 mm long, 2.4–3.4 cm; apex retuse, sinus 1–2 mm deep, base shallowly 2-flowered; bracts absent; pedicels 8–12 mm long, indumen- and broadly cordate or rounded; lower surface with a forward- tum as midrib, c. 100 % cover; tepals 4, ovate-oblong 5–6 by directed pocket, 1–2 mm long, 2.5 mm wide, set back 2–3 mm 2.5 mm, outer surface with white appressed hairs c. 0.1 mm from the midline apex, the pocket sides continued to apex by long, c. 5 % cover, absent from base; inner surface with large two ridges; mouth of pocket and marginal 2–3 mm of the lid, mi- elliptic glands. Fruit valves 4, narrowly linear-elliptic, 2.5–3.6 nutely stellate-hairy, lacking nectar glands, the hairs c. 0.1 mm by 0.2–0.3 cm, pale brown, 60 % covered by curved red hairs diam with (2–)3–4(–5) short, thick arms, covering c. 50 % c. 0.4 mm long. Seeds pale brown, filiform, 14 mm long, seed of the surface at the edge itself, giving it a grey, shaggy appear- body 1.25 by 0.3–0.4 mm, deeply corrugated. ance; basal appendage conspicuous, semi-circular to oblong, Distribution & Ecology — Philippines, Mindanao, S Cotabato asymmetric, 1.5–2 by 2 mm, arising abruptly from a ridge Province, T’boli, Lake Parker, open grassland, 1463 m. 6 mm long, 1.25 mm high; nectar glands trimorphic, segregated: Conservation — Here, N. tboli is assessed as Critically En- 1. Large, elliptic-oblong, thinly bordered nectar glands 1–1.25 dangered under criterion D of IUCN (2012) since it is currently by 0.6–1 mm, 15–20 in number, present in a band 6 mm known only from one or two mature individuals at the type wide, along the midline between basal ridge and apex, locality which is threatened by plantation agriculture and tour- sparse; smaller such glands 0.3–0.35 by 0.25 mm sparsely ism developments (Google Earth data). It is to be hoped that scattered in the distal half outside the midline and in the more individuals of the species will be found at other locations, proximal half inside the margin, throughout the lid mixed hopefully in the extensive yet botanically poorly known Tiruray with small sessile red globose glands c. 0.05 mm diam, c. 10 Highlands of the T’boli people in southern Mindanao, and that per mm2 (Fig. 2i); this species will be shown to be more common than present 2. small, circular, thickly rimmed (perithecoid) nectar glands, evidence suggests. (0.15–)0.25 mm diam, confined to the basal appendage Notes — Nepenthes tboli is morphologically most similar to and to two curved elliptic areas on each side of the midline N. saranganiensis Sh.Kurata (2003: 41), but lacks the strongly in the proximal half, glands very dense, 13 per mm2 on the winged stems of N. saranganiensis, a feature unique to this appendage and abutting each other there (Fig. 2h); species within the N. alata group. Nepenthes saranganiensis 3. small, deeply sunk borderless, circular glands 0.1–0.2 mm is nearly sympatric with N. tboli and is the only other species diam, c. 5 per mm2 present in a small area at the junction of the genus known thus far, from the extreme S of Mindanao. with the peristome. The two species can be differentiated using Table 2. Spur simple, needle-like, tapering to a point, 10 by 0.3 mm, Nepenthes tboli is unusual in the N. alata group in possessing erect; indumentum as outer pitcher surface. Male inflores- a pocket in the lower surface of the lid, at the apex (Fig. 2j). cence known from incomplete portion, rhachis 2.5 mm diam, Such lid pockets occur in few other species of the genus, e.g. M. Cheek & M. Jebb: Expansion of the Nepenthes alata group 151

N. albomarginata Lindl., and are otherwise known in Mindanao tall) pitchers; nectar glands and indumentum resembling those species only in N. robcantleyi Cheek (2011) and in N. graciliflora. of upper pitchers but sparser. Spur triangular c. 2.5 by 1.5 mm, The function of such pockets is unknown, but we speculate tapering from base to rounded apex; densely covered in brown that they are associated with attraction of prey, possibly by bushy and ‘dagger hairs’ 0.3–1 mm long. Upper pitchers (tendril holding nectar. coiled) ellipsoid-cylindric (9–)16–25 by (2.6–)4–5.5 cm, wid- est in the basal ellipsoid, 7–8 cm long portion, above cylindric Nepenthes zygon Jebb & Cheek, sp. nov. — Fig. 3 narrowed to (1.8–)2.5–3(–3.5) cm diam; indumentum as lower pitchers, colour when live with basal, swollen part of pitcher Differs from N. mindanaoensis Sh.Kurata, in having leaf blades narrowly green (drying brown), overlain with white waxy layer, cylindrical oblong-elliptic (not ovate-lanceolate), petiole with wings patent (not strongly involute, appearing cylindric), basal lid appendage present in upper pitch- part with faint to well-marked longitudinal red-purple stripes and ers, conspicuous, strongly convex or hooked (not inconspicuous or weakly flecks, inner pitcher surface waxy green (drying pale purple), developed). — Type: Cheek 17059 (holotype K; isotypes L, PNH), Philip- spotted with purple; fringed wings present only immediately pines, Mindanao Island, Mt Pasian, seed collected in 1997 by R. Cantley, below the peristome (0.6–)1.7–3.5 cm long, widest at the cultivated at Royal Botanic Gardens, Kew as accession 2004-2413, male peristome where (1–)2.5–7.5 mm wide, fringed elements 3–6 infl. Sept. 2013. mm long, 1.5–3 mm apart, the uppermost longest and raised Synonymy. Nepenthes alata Blanco var. ecristata sensu Macfarlane (1927) above the peristome; mouth ovate, 3.5–5 by 2.5–3.3 cm, 137 non Macfarl. (1908) 72, quoad Elmer 14248. oblique, slightly concave, column weakly developed; peristome Nepenthes alata sensu Danser (1928) 261 non Blanco, quoad Elmer subcylindric (flattened only before the pitcher is fully opened Fig. 14248. 3b) (1.5–)2–3(–5) mm broad, ribs 0.3 mm apart, about 0.01 Etymology. The epithet zygon, here used as a noun in apposition, derives mm high, outer margin entire, revolute, inner margin without from the Greek, meaning yoked or coupled, to signify the close linkage with conspicuous teeth, revolute (edge with holes visible only when N. mindanaoensis. dissected, (Fig 3q), green or red and green in colour; lid ovate Terrestrial climber 2–3 m tall, possibly sometimes rooting on (2.2–)3.3–4.5(–4.9) by 2.5–4(–4.6) cm, apex rounded or bases of stunted trees in cloud forest. Stem terete, 5.5–9.5 slightly retuse, base cordate, the sinus 1–1.5 cm wide, 5 mm mm diam. Rosette and short stems not well-developed. Climb- deep, lower surface with a basal ridge 1.5 cm long, rising gradu- ing stems with internodes (2.8–)5–12 cm long, axillary buds ally to 0.5–1 mm high, tapering to the extremities, and bearing filiform 5(–7) by 0.9 mm long, inserted 6–9 mm above the in the centre a convex or recurved-hooked appendage (Fig. 3n) axil, indumentum of patent brown ‘dagger hairs’ (Kurata 2003) projecting 3–4 mm from the lid surface, 4–7 mm long; nectar 0.2–0.5(–0.8) mm long, very sparse to 20–30 % surface glands are of two types and mostly confined to two approxi- coverage, denser in leaf axils; sessile red depressed-globose mately lanceolate areas, which are joined at the basal ridge, glands 0.05 mm diam, scattered throughout. Leaves thinly nectar glands being largely absent from a marginal band 5–8 coriaceous, petiolate. Rosette leaves oblanceolate, 14–18 by mm wide and from the distal half of the midline; they are thinly 4–4.5 cm. Leaves of climbing stems narrowly oblong-elliptic, scattered on the basal appendage; type 1: nectar glands (90 % 21–24(–30) by 2.8–5.5(–7) cm; apex acute, not peltate; base of the total c. 1 per mm2) are small, thinly bordered, orbicular or decurrent to petiole; longitudinal nerves 1–2 pairs, 2–10 mm elliptic, 0.1–0.2 mm in length; type 2: nectar glands are similar from the margin, arising from the midrib of the blade, conspicu- in appearance, but much sparser and larger 0.5–0.6(–0.7) mm ous above; pennate nerves numerous, patent, conspicuous long; sessile red-black depressed-globose glands 0.05 mm above; midrib upper surface 20–30 % covered in a mixture diam, c. 3 per mm2 are scattered over the whole of the lower of dark brown simple or ‘dagger hairs’ 0.06–1 mm long and surface; marginal 2–3 mm 50 % covered in stalked bushy white, (2–)3–6-armed bushy to substellate hairs 0.2–0.25 mm brown hairs 0.1–0.2 mm diam, several occurring towards the diam, margin densely shortly hairy with same hairs (Fig. 3e), centre of the lid, 8–10 mm from the edge; spur simple, filiform, blade otherwise mainly lacking hairs except thinly scattered 5–9 mm long, 0.5 mm wide, apex obtuse, densely covered in white hairs; sessile, red depressed-globose glands 0.05 mm appressed hairs 0.5–1 mm long. Male inflorescence c. 47 by 3.5 diam scattered throughout; lower surface with midrib 10–20 % cm, indumentum moderately dense, covering 40–50 % of the covered in dark brown ‘dagger hairs’ 0.5–0.6 mm long, mixed surface, hairs pale brown, a mixture of ‘dagger hairs’ 0.5–1 mm with substellate pale brown bushy hairs arising from a dark red long, and 2–4-armed bushy hairs 0.2–0.25 mm long; peduncle base, 4–6-armed, 0.15–0.2 mm diam, extending very sparsely c. 27 by 0.3 cm; rhachis c. 20 cm long, with partial-peduncles to the blade (i.e. Elmer 14248) or moderately densely c. 3 hairs 75–80, 2-flowered (1-flowered at apex); bracts recurved or mm2; margin densely ciliate with hairs as in upper surface of patent, filamentous, c. 3 mm long, acute, inserted along the midrib. Petiole winged, broadly U- or V-shaped in section, length of the partial-peduncles; partial-peduncles 4–6 mm long; (6–)7–10 by 0.6–1(–2) cm. Lower pitchers (tendril not coiled) pedicels c. 15 mm long, indumentum covering 30–50 % of the ellipsoid-cylindric, 9–14 by 2.5–5 cm, widest in the ellipsoid surface, hairs bushy, 1–3-armed, erect, 0.2–0.5 mm long; te- lower half, upper half cylindric 1.5–2.5 cm wide; fringed wings pals 4, elliptic, 6 by 4 mm, outer surface 50–60 % covered in a present from base to peristome, wings 3–4 mm wide, fringe mixture of simple, acute hairs 0.15–0.25 mm long, and sessile elements 4–5 mm long, (2–)3–5.5 mm apart; outer surface mucilaginous papillae 0.005 mm diam, inner surface densely 30–50 % covered in minute (3–)4-armed stellate hairs 0.1 mm covered in elliptic nectar glands; staminal column 5 mm long, diam, mixed with sparser (c. 5 % cover) hairs 0.75–1.3 mm long superficially simple but bearing 1–2 short side branches from moderately densely hairy along its length, hairs 0.1 mm long, the central axis (Fig. 3j). Mouth ovate-elliptic, 2.5–4 by 1.7–2 more or less patent, red-brown, simple or with a basal branch; cm, oblique, not, or only weakly concave, column not present; anther-head subglobose, 2.5 mm diam. Female inflorescences, peristome cylindric 2–4 mm diam, even in width throughout, infrutescences and seed unknown. ribs 0.5–0.6 mm apart, raised 0.4 mm, in life the inner edge Distribution & Ecology — Philippines, NE Mindanao, Mts appears to be without teeth or holes, which can be found on Masay and Pasian, submontane mossy forest along ridges, dissection, outer edge not lobed. Lid orbicular-elliptic, 2–2.5 by thought to be non-ultramafic, 1500–1875 m asl.

1.8–2.9 cm, apex rounded, base slightly cordate; basal ridge Additional material. Philippines, Mindanao, Mt Masay (also known as Mt and appendage absent in the smaller pitchers (c. 10 cm tall), Cabadbaran and Mt Urdaneta), Elmer 14248 (E, L), “in the summit region resembling those of the upper pitchers in the larger (c. 15 cm at approx. 6250 feet alt., Oct. 1912” (Elmer 1915). 152 Blumea – Volume 59 / 2, 2014

m l

g h o n

i r

q p k

f

d e

c

b a j Fig. 3 Nepenthes zygon Jebb & Cheek. a. Habit, climbing stem with male inflorescence and upper pitcher; b. upper pitcher, not yet fully opened; c. lower pitcher; d. leaf-blade, upper surface showing midrib hairs; e. leaf-blade, marginal hairs; f. rhachis indumentum; g. partial-peduncle with male flowers; h. pedi- cel indumentum; i. tepal, lower surface indumentum; j. upper pitcher, outer surface indumentum; k. tendril indumentum; l. lid of upper pitcher showing nectar gland distribution and basal appendage; m. lid, lower surface, detail of glands; n. lid basal appendage (inverted); o. spur, upper pitcher; p. peristome viewed from above; q. peristome, viewed from inside pitcher, unrolled to expose inner edge; r. peristome, transverse section, immature, outer surface on right (a–k, m–r. from Cheek 17059 (drawn from live material); l. from Elmer 14248 (E). — Scale bars: a–c = 5 cm; d–f, h, i, k = 1 mm; g, l, n = 1 cm; j = 2 mm; m, o–r = 2 mm. Drawing by Andrew Brown. M. Cheek & M. Jebb: Expansion of the Nepenthes alata group 153

Conservation — Nepenthes zygon is known with certainty from Variation — The two collections vary from each other in den- only two individuals at two locations, in a country which has sity of indumentum on the stem and lower surface of the leaf- seen loss of most of its natural habitat in the 20th century blade of the climbing stem (very sparse in Cheek 17059, mod- (Myers et al. 2000, Sohmer & Davis 2007). Nepenthes zygon erately dense in Elmer 14248) and in the density of the nectar shares its type location, Mt Pasian, with N. robcantleyi. The glands on the lower surface of the lid of the upper pitcher, which clear-felling of forest there that led to the concern that N. rob- is much sparser in Elmer 14248 than in Cheek 17059. In all cantleyi might be extinct (Cheek 2011) may also have elimi- other respects, the two specimens appear more or less identi- nated N. zygon at that location. However at its second loca- cal, e.g. in the unusual trichome complement of the leaf-blade tion, Mt Masay, no threats are yet known to summit areas midribs and lower lid surface. where N. zygon was collected (Gronemeyer pers. comm. to Notes — “Three or more distinct terrestrial species” (of Ne- MC). Recent photographic records of what may be this spe- penthes) were observed “in the summit region or about 5000 cies (identified as N. alata in Gronemeyer 2008: 26, 2009: 7) feet” by Elmer on Mt Masay (also known as Mt Urdaneta or Mt at Mt Masay suggests that it survives there. A similar image Cabadbaran) (Elmer 1915). These were all collected by Elmer: from Mt Hibok-Hibok (Gronemeyer 2008: 25) suggests that N. surigaoensis Elmer (Elmer 12705 in Sept. 1912), N. petiolata N. zygon may also be present there, yet all three images do Danser (1928) which had been collected by Elmer as a mixed not provide enough detail that identification is certain. Accord- gathering with the first species, although Elmer had suspected ingly, N. zygon is here assessed as Critically Endangered under that it was different when he had collected it (Elmer 1915). IUCN (2012), criterion D based on less than 50 individuals (in Thirdly, newly described here from the same locality (although fact two) being known from the wild with certainty. It is to be the altitude given is higher), N. zygon (collected in Oct. 1912). hoped that the species will be verified at the locations named From neighbouring peaks “at a lower elevation there is the high above, found at additional locations and so proved to be not so epiphytic species N. truncata Macf.“ (Elmer 1915), which Elmer rare or threatened as existing data suggest. It is fortunate that had collected earlier in Aug. 1912 although he gave it a higher N. zygon is already in cultivation and available commercially collection number (Elmer 13483, BM, Urdaneta). from the nursery Borneo Exotics. Taxonomic affinities — Although N. zygon has previously Macfarlane (1927) in his final paper of Philippine Nepenthes, been identified as N. alata in the broad sense, recent research misidentified Elmer 14248 citing it as N. alata var. ecristata Macfarl. (1908: 72), the type of which is now raised to species has shown that the latter species is confined to northern Luzon rank as N. kurata Jebb & Cheek (2013h). It can be distinguished and differs in a number of characters (see key). Nepenthes using the key above. Danser (1928) cited the same specimen zygon appears to be closely related to N. mindanaoensis, simply as N. alata, taking a wide view on the delimitation of being very similar in overall appearance. Their geographic this species. ranges coincide, but ecologically they are separated by their habitat and altitudinal range, N. zygon being restricted to cloud In life (Cheek 17059), the colour and aspect of the upper pit­ forest on non-ultramafic substances, while N. mindanaoensis chers is very different from the herbarium specimens (Elmer is restricted to low altitude ultramafic scrub. Nepenthes zygon 14248), but once the former had been dried, these features lacks the diagnostic petiole of N. mindanaoensis in which the became identical to the second, although made 101 years later. wings are so involute that their margins overlap each other so Nepenthes zygon, although newly described here, is already that the petiole appears cylindrical. Nepenthes zygon also has one of the better-known Mindanao species of the genus, be- a well-developed basal appendage to the lid (vs being absent), cause it has been possible to observe authentic wild-sourced besides differing in the other characters given in Table 3. material in cultivation from the juvenile stage to flowering, and Nepenthes zygon has several features unusual in the genus, so to develop a nearly complete description. This approach is and which are otherwise unknown in the N. alata group. These also used in Araceae where leaves and inflorescences do not are: occur on the plant at the same time so that cultivation is the 1. the white waxy bloom that coats the lower half of the upper best way to reliably connect the different stages for descriptive pitchers; purposes. 2. the presence of hairs in the centre of the lower surface of The basal ridge and appendage that characterise the N. alata the lid of the pitcher; and group, and which are present in the upper pitchers of N. zygon, 3. the dense patent hairs of the androphore (although male are completely absent from its lower pitchers. Whether this is inflorescences are not known for all species of the group). usual or not throughout the species of the group remains to be determined. Table 3 The more important diagnostic characters separating N. mindana­ oensis and N. zygon. Acknowledgements Janis Shillito typed the paper, Aaron Davis advised on, and Tiana Rehman accessed, the BRIT material, Kanchi Gandhi provided Nepenthes mindanaoensis Nepenthes zygon the Kurata (2003) reference. Robert Cantley (Borneo Exotics) collected seed Leaf-shape Ovate-lanceolate Narrowly oblong-elliptic and provided the live material of N. zygon which James Beattie, Nick Johnson Petiole Wings involute, appearing Wings ± patent, broadly and Rebecca Hilgenhoff grew to flowering stage at RBG, Kew. The authors cylindric, 0-shaped in V-shaped or U-shaped in are grateful to two anonymous reviewers for their comments resulting from transverse section transverse section scrutiny of an earlier version of this manuscript. No. and origin of 2–3 arising from petiole 1–2 arising from midrib longitudinal nerve of blade pairs REFERENCES Length of ‘dagger (1–)1.5–2 mm 0.2–0.5(–1) mm hairs’ on stem, Cheek M. 2011. Nepenthes robcantleyi sp. nov. (Nepenthaceae) from Min- petiole and midrib danao, Philippines. Nordic Journal of Botany 29: 677–681. Leaf-blade base Blade abruptly contracted Blade decurrent into Cheek M, Jebb M. 2001. Nepenthaceae. In: Nooteboom HP (ed), Flora into petiole petiole Malesiana, Ser. I, 15. Nationaal Herbarium Nederland, Leiden. Basal lid appendage Not well-developed, or Strongly convex to hooked, Cheek M, Jebb M. 2013a. Typification and redelimitation of Nepenthes alata absent, inconspicuous conspicuous in upper pitch- Blanco with notes on the N. alata group, and N. negros sp. nov. from the ers, but absent in lower ones Philippines. Nordic Journal Botany 31, 5: 616–622. Habitat Scrub on ultramafic soils Submontane forest Cheek M, Jebb M. 2013b. Nepenthes alzapan (Nepenthaceae), a new spe- Altitude range 200–300 m 1500–1875 m cies from Luzon, Philippines. Phytotaxa 100, 1: 57–60. 154 Blumea – Volume 59 / 2, 2014

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